Imaging device

ABSTRACT

An imaging device includes: a semiconductor substrate including a pixel region in which pixels are arranged and a peripheral region adjacent to the pixel region; an insulating layer that covers the pixel region and the peripheral region; a first electrode located on the insulating layer above the pixel region; a photoelectric conversion layer that covers the first electrode; a second electrode that covers the photoelectric conversion layer; detection circuitry located in the pixel region and connected to the first electrode; peripheral circuitry located in the peripheral region and connected to the detection circuitry; and a third electrode located on the insulating layer above the peripheral region. The second electrode extends above the peripheral region, and the second electrode includes a connection region in which the second electrode is connected to the third electrode, the connection region overlapping the peripheral circuitry in plan view.

BACKGROUND 1. Technical Field

The present disclosure relates to an imaging device.

2. Description of the Related Art

Japanese Patent No. 5637751 (hereinafter referred to as “Patent Document1”) discloses an organic-film stack-type solid-state imaging device. Asolid-state imaging device disclosed in Patent Document 1 includes aphotoelectric converting section having a structure in which aphotoelectric conversion layer is sandwiched between an upper electrodeand lower electrodes. A voltage is supplied to the upper electrode viaconnection electrodes. In the technology disclosed in Patent Document 1,a connection region is arranged in addition to a pixel region andperipheral circuitry, such as a vertical driver, a columnanalog-to-digital converter (ADC), and a horizontal driver. Theconnection region is a region in which the upper electrode and theconnection electrodes are connected to each other. The connection regionis arranged between the pixel region and a pad.

SUMMARY

In imaging devices, it is desired that an increase in chip areas besuppressed. Also, in stack-type image sensors, it is desired to enhancethe adhesion between an upper electrode and a photoelectric conversionlayer and the adhesion between the photoelectric conversion layer andlower electrodes.

In one general aspect, the techniques disclosed here feature an imagingdevice including: a semiconductor substrate including a pixel region inwhich pixels are arranged and a peripheral region adjacent to the pixelregion; an insulating layer that covers the pixel region and theperipheral region; a first electrode located on the insulating layerabove the pixel region; a photoelectric conversion layer that covers thefirst electrode; a second electrode that covers the photoelectricconversion layer; detection circuitry located in the pixel region andconnected to the first electrode; peripheral circuitry located in theperipheral region and connected to the detection circuitry; and a thirdelectrode located on the insulating layer above the peripheral region.The second electrode extends above the peripheral region, and the secondelectrode includes a connection region in which the second electrode isconnected to the third electrode, the connection region overlapping theperipheral circuitry in plan view.

It should be noted that general or specific embodiments may beimplemented as an element, a device, an apparatus, or any selectivecombination thereof.

Additional benefits and advantages of the disclosed embodiments willbecome apparent from the specification and drawings. The benefits and/oradvantages may be individually obtained by the various embodiments andfeatures of the specification and drawings, which need not all beprovided in order to obtain one or more of such benefits and/oradvantages.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view illustrating one example of a planar structure of animaging device according to a first embodiment;

FIG. 2 is a schematic sectional view taken along line II-II in FIG. 1;

FIG. 3 is a view illustrating one example of a planar structure of animaging device according to a second embodiment;

FIG. 4 is a view illustrating one example of a planar structure of animaging device according to the second embodiment;

FIG. 5 is a schematic sectional view taken along line V-V in FIG. 3;

FIG. 6 is a view illustrating one example of a planar structure of animaging device according to a modification of the second embodiment;

FIG. 7 is a schematic sectional view taken along line VII-VII in FIG. 6;

FIG. 8 is a view illustrating one example of a planar structure of animaging device according to a third embodiment;

FIG. 9 is a view illustrating one example of a planar structure of animaging device according to the third embodiment;

FIG. 10 is a schematic sectional view taken along line X-X in FIG. 8;

FIG. 11 is a view illustrating one example of a cross-sectionalstructure of an imaging device according to a first modification of thethird embodiment;

FIG. 12 is a view illustrating one example of a cross-sectionalstructure of an imaging device according to a second modification of thethird embodiment;

FIG. 13 is a view illustrating one example of a planar structure of animaging device according to a fourth embodiment;

FIG. 14 is a view illustrating one example of a planar structure of animaging device according to the fourth embodiment;

FIG. 15 is a schematic sectional view taken along line XV-XV in FIG. 13;

FIG. 16 is a view illustrating one example of a planar structure of animaging device according to another embodiment;

FIG. 17 is a schematic sectional view taken along line XVII-XVII in FIG.16; and

FIG. 18 is a diagram illustrating one example of a camera systemincluding the imaging device in the present disclosure.

DETAILED DESCRIPTION (Findings of Present Inventors)

In the technology disclosed in Patent Document 1, the connection regionis arranged in a region other than the pixel region and a peripheralregion including the peripheral circuitry. Consequently, there is aproblem in that the chip area increases.

As a result of carrying out extensive and earnest study in view of theforegoing situation, the present inventors have found that an increasein the chip area can be suppressed by arranging the connection regionand the peripheral region so that they overlap each other in plan view.Also, there are cases in which, for example, material, such as organicmaterial, with which the force of adhesion between the lower electrodesand the insulating layer and between the insulating layer and the upperelectrode is small is used as material of the photoelectric conversionlayer. The present inventors have found that, even in such cases, theadhesion between the lower electrodes and the insulating layer and theadhesion between the insulating layer and the upper electrode can beenhanced by covering the entire photoelectric conversion with the upperelectrode.

An overview of one aspect of the present disclosure will be describedbelow.

[Item 1]

An imaging device includes:

a semiconductor substrate including a pixel region in which pixels arearranged and a peripheral region adjacent to the pixel region;

an insulating layer that covers the pixel region and the peripheralregion;

a first electrode located on the insulating layer above the pixelregion;

a photoelectric conversion layer that covers the first electrode;

a second electrode that covers the photoelectric conversion layer;

detection circuitry located in the pixel region and connected to thefirst electrode;

peripheral circuitry located in the peripheral region and connected tothe detection circuitry; and

a third electrode located on the insulating layer above the peripheralregion, wherein

the second electrode extends above the peripheral region, and

the second electrode includes a connection region in which the secondelectrode is connected to the third electrode, the connection regionoverlapping the peripheral circuitry in plan view.

[Item 2]

In the imaging device according to item 1,

the peripheral circuitry includes a transistor, and

the connection region overlaps the transistors in the plan view.

[Item 3]

In the imaging device according to item 1,

the peripheral circuitry includes analog circuitry connected to thedetection circuitry, and

the connection region overlaps the analog circuitry in the plan view.

[Item 4]

In the imaging device according to item 3,

the analog circuitry includes a transistor, and

the connection region overlaps the transistors in the plan view.

[Item 5]

In the imaging device according to item 1,

the peripheral circuitry includes digital circuitry connected to thedetection circuitry, and

the connection region overlaps the digital circuitry in the plan view.

[Item 6]

In the imaging device according to item 5,

the digital circuitry includes a transistor, and

the connection region overlaps the transistors in the plan view.

[Item 7]

In the imaging device according to item 5 or 6,

the peripheral circuitry includes analog circuitry connected between thedigital circuitry and the detection circuitry, and

the connection region does not overlap the analog circuitry in the planview.

[Item 8]

In the imaging device according to item 1,

the peripheral circuitry includes

-   -   analog circuitry connected to the detection circuitry,    -   a wire connected to the analog circuitry, and    -   digital circuitry connected to the analog circuitry through the        wires; and

the connection region overlaps the wires in the plan view.

[Item 9]

In the imaging device according to item 1,

the peripheral circuitry includes

-   -   analog circuitry connected to the detection circuitry, and    -   a wire for connecting the analog circuitry to external        circuitry, and

the connection region overlaps the wire in the plan view.

[Item 10]

In the imaging device according to one of items 1 to 9,

the second electrode includes, above the peripheral region, a firstregion in which the photoelectric conversion layer is not presentbetween the second electrode and the insulating layer, and

the first region includes the connection region and a non-connectionregion other than the connection region.

[Item 11]

In the imaging device according to item 10,

in a direction from the pixel region toward the peripheral region, thenon-connection region has a length that is greater than a length of theconnection region.

[Item 12]

In the imaging device according to one of items 1 to 11,

in the plan view, the second electrode has an area that is larger thanan area of the pixel region.

[Item 13]

The imaging device according to one of items 10 to 12 further includes ashield wire located, in the plan view, between the non-connection regionand the peripheral circuitry or between the non-connection region and awire connected to the peripheral circuitry.

[Item 14]

In the imaging device according to item 13,

the peripheral circuitry includes analog circuitry, and

the shield wire is located, in the plan view, between the non-connectionregion and the analog circuitry or between the non-connection region anda wire connected to the analog circuitry.

[Item 15]

In the imaging device according to one of items 1 to 14,

the plurality of pixels are arranged on the pixel region in a matrix,and

the connection region is arranged along two or more sides of the pixelregion.

[Item 16]

In the imaging device according to one of items 1 to 15,

the second electrode covers more than half of first electrodes locatedabove the pixel region.

[Item 17]

In the imaging device according to one of items 1 to 16,

the third electrode and the first electrodes are in contact with asingle continuous layer.

[Item 18]

In the imaging device according to one of items 1 to 17,

the third electrode contains a material that is the same as a materialthat the first electrode contains.

[Item 19]

In the imaging device according to one of items 1 to 18,

the third electrode contains at least copper, tungsten, titanium,tantalum, or aluminum.

[Item 20]

In the imaging device according to one of items 1 to 19, the secondelectrode covers an entire portion of the photoelectric conversionlayer.

An imaging device according to one aspect of the present disclosureincludes: a semiconductor substrate, a pixel region in which a pluralityof pixels is arranged above the semiconductor substrate in a matrix, anda peripheral region arranged at a periphery of the pixel region in planview and including peripheral circuitry. The pixel region includes lowerelectrodes, an upper electrode that opposes the lower electrodes, aphotoelectric conversion layer provided between the lower electrodes andthe upper electrode, and detection circuitry located above thesemiconductor substrate to detect potentials of the lower electrodes.The upper electrode has a first region that overlaps the peripheralregion in plan view, and the first region includes a connection regionin which the upper electrode is connected to a connection electrodecontaining material that is different from material of the upperelectrode.

According to the above-described configuration, since the upperelectrode has the first region that overlaps the peripheral region, andthe first region includes the connection region in which the upperelectrode is connected to the connection electrode, the connectionregion is arranged so as to overlap the peripheral region in plan view.This makes it possible to suppress an increase in the chip area.

For example, in the imaging device according to one aspect of thepresent disclosure, the first region may further have a non-connectionregion, which is not connected to the connection electrode in plan view.

According to the above-described configuration, since the first regionhas the connection region and the non-connection region, the area inwhich the first region overlaps the peripheral region increases.Accordingly, an increase in the chip area can be suppressed, comparedwith a case in which the first region and the peripheral region arearranged so that they do not overlap each other. Also, since the firstregion has the connection region and the non-connection region, it ispossible to increase the area in which the upper electrode covers thephotoelectric conversion layer, the lower electrodes, and peripheralportions thereof. This makes it possible to enhance the adhesion betweenthe upper electrode and the photoelectric conversion layer and theadhesion between the photoelectric conversion layer and the lowerelectrodes.

For example, in the imaging device according to one aspect of thepresent disclosure, the upper electrode may have a larger area than anarea of the pixel region in plan view.

There are cases in which, for example, material, such as organicmaterial, with which the force of adhesion between the lower electrodesand the insulating layer and between the insulating layer and the upperelectrode is small is used as material of the photoelectric conversionlayer. Even in such a case, according to the above-describedconfiguration, since the upper electrode covers the entire photoelectricconversion layer, it is possible to enhance the adhesion between theupper electrode and the photoelectric conversion layer and the adhesionbetween the photoelectric conversion layer and the lower electrodes.

For example, in the imaging device according to one aspect of thepresent disclosure, the peripheral circuitry may have digital circuitry,and the first region may overlap the digital circuitry in plan view.

According to the above-described configuration, since at least one ofthe non-connection region and the connection region is arranged abovethe digital circuitry, which is robust against noise, it is possible tofurther suppress an increase in the chip area, without impairingcharacteristics of the peripheral circuitry. Also, since the firstregion is arranged to extend to the digital circuitry in plan view, thearea of the first region increases. This makes it possible to increasethe area in which the upper electrode covers the photoelectricconversion layer and the lower electrodes, thus making it possible toenhance the adhesion between the upper electrode and the photoelectricconversion layer and the adhesion between the photoelectric conversionlayer and the lower electrodes.

For example, in the imaging device according to one aspect of thepresent disclosure, the peripheral circuitry may have analog circuitrylocated between the pixel region and the digital circuitry, and in planview, the non-connection region may overlap the analog circuitry, andthe connection region may overlap the digital circuitry.

According to the above-described configuration, since the connectionregion is arranged above the digital circuitry, which is robust againstnoise, and the non-connection region is arranged on analog circuitry,which is susceptible to noise, it is possible to reduce influences ofnoise on the peripheral circuitry.

For example, in the imaging device according to one aspect of thepresent disclosure, the peripheral region may have digital circuitry anda wire region located between the pixel region and the digital circuitryand including wires connected to the digital circuitry, and the firstregion may overlap the wire region in plan view.

According to the above-described configuration, since the first regionis arranged above the wires, it is possible to suppress an increase inthe chip area, without impairing characteristics of the peripheralcircuitry. Also, since the first region is arranged to extend to thewire region in plan view, the area of the first region increases. Thismakes it possible to increase the area in which the upper electrodecovers the photoelectric conversion layer and the lower electrodes, thusmaking it possible to enhance the adhesion between the upper electrodeand the photoelectric conversion layer and the adhesion between thephotoelectric conversion layer and the lower electrodes.

For example, in the imaging device according to one aspect of thepresent disclosure, the peripheral region may have analog circuitrylocated between the pixel region and the wire region, and in plan view,the non-connection region may overlap the analog circuitry, and theconnection region may overlap the wire region.

According to the above-described configuration, since the connectionregion is arranged above the wires, and the non-connection region isarranged above the analog circuitry, which is susceptible to noise, itis possible to reduce influences of noise on the peripheral circuitry.

For example, in the imaging device according to one aspect of thepresent disclosure, the peripheral circuitry may have analog circuitry,and the first region may overlap the analog circuitry in plan view.

According to the above-described configuration, the first region isarranged to extend to above the analog circuitry. This makes it possibleto increase the area in which the upper electrode covers thephotoelectric conversion layer and the lower electrodes in plan view.Thus, it is possible to enhance the adhesion between the upper electrodeand the photoelectric conversion layer and the adhesion between thephotoelectric conversion layer and the lower electrodes.

For example, the imaging device according to one aspect of the presentdisclosure may have a shield wire that is located between the pixelregion and the connection region in plan view and that is locatedbetween wires that connect to the peripheral circuitry and the upperelectrode in a plane orthogonal to the semiconductor substrate.

According to the above-described configuration, since the shield wire isarranged between the wires that are connected to the peripheralcircuitry and the upper electrode in a plane orthogonal to thesemiconductor substrate, the peripheral circuitry and the wires can beprotected against external noise.

For example, in the imaging device according to one aspect of thepresent disclosure, the connection region may be arranged along two ormore sides of the pixel region.

According to the above-described configuration, since the connectionregion is arranged along two or more sides of the pixel region, the areaof the first region is further increased in plan view, compared with acase in which the connection region is arranged along one side of thepixel region. This makes it possible to increase the area in which theupper electrode covers the photoelectric conversion layer and the lowerelectrodes, thus making it possible to enhance the adhesion between theupper electrode and the photoelectric conversion layer and the adhesionbetween the photoelectric conversion layer and the lower electrodes.

For example, in the imaging device according to one aspect of thepresent disclosure, the upper electrode may cover more than half of thelower electrodes located in the pixel region.

According to the above-described configuration, since the upperelectrode covers more than half of the lower electrodes located in thepixel region, it is possible to increase the area in which the upperelectrode covers the photoelectric conversion layer and the lowerelectrodes in the pixel region. Thus, it is possible to enhance theadhesion between the upper electrode and the photoelectric conversionlayer and the adhesion between the photoelectric conversion layer andthe lower electrodes.

For example, in the imaging device according to one aspect of thepresent disclosure, the connection electrode may be located on a layerthat is the same as a layer of the lower electrodes.

According to the above-described configuration, since the connectionelectrode is located on a layer that is the same as a layer of the lowerelectrodes, the lower electrodes and the connection electrode can beformed in the same process during manufacture. Accordingly, the numberof manufacturing processes can be reduced, thus making it possible toreduce the time and cost for the manufacture.

For example, in the imaging device according to one aspect of thepresent disclosure, the connection electrode may contain material thatis the same as material of the lower electrodes.

According to the above-described configuration, since the connectionelectrode contains material that is the same as material of the lowerelectrodes, the connection electrode can be formed of material that isthe same as material of the lower electrodes. Thus, for example, whenthe connection electrode is formed on a layer that is the same as alayer of the lower electrodes during manufacture, these electrodes canbe formed at the same time. Accordingly, the number of manufacturingprocesses can be reduced, thus making it possible to reduce the time andcost for the manufacture.

For example, in the imaging device according to one aspect of thepresent disclosure, the connection electrode may contain at least one ofCu, W, Ti, Ta, and Al.

According to the above-described configuration, the connection electrodecan be formed without adding a new process to a currently availablecomplementary metal-oxide semiconductor (CMOS) process.

For example, in the imaging device according to one aspect of thepresent disclosure, the upper electrode may cover the entirephotoelectric conversion layer.

According to the above-described configuration, since the upperelectrode covers the entire photoelectric conversion layer, the upperelectrode can cover all the pixels included in the pixel region. In thiscase, since the upper electrode has the first region that overlaps theperipheral region in plan view, it is possible to increase the area inwhich the upper electrode covers the photoelectric conversion layer andthe lower electrodes. This makes it possible to enhance the adhesionbetween the upper electrode and the photoelectric conversion layer andthe adhesion between the photoelectric conversion layer and the lowerelectrodes.

Embodiments of the present disclosure will be described below in detailwith reference to the accompanying drawings.

The embodiments described below each represent a general or specificexample. Numerical values, shapes, materials, constituent elements, thearrangement and the connection forms of constituent elements, steps, theorder of steps, and so on described in the embodiments below areexamples and are not intended to limit the present disclosure. Variousaspects described herein can be combined together, as long as such acombination does not cause contradiction. Also, of the constituentelements in the embodiments below, constituent elements not set forth inthe independent claim that represents the broadest concept will bedescribed as optional constituent elements. Each figure does notnecessarily strictly depict each configuration. In the followingdescription, constituent elements having substantially the samefunctions are denoted by the same reference numerals, and redundantdescriptions may be omitted or simplified.

In the imaging device according to one aspect of the present disclosure,a photoelectric converting section that photoelectrically convertsincident light into electrical signals is provided in an upper layer,and a signal processing circuitry portion including silicon-based CMOScircuitry that outputs the electrical signals, obtained by thephotoelectric converting section, to outside is provided in a lowerlayer. Thus, in the imaging device according to one aspect of thepresent disclosure, since the photoelectric converting section and thesignal processing circuitry portion are stacked, they can be designedindependently.

First Embodiment

An overall configuration of an imaging device according to a firstembodiment will be described with reference to FIGS. 1 and 2. FIG. 1 isa view illustrating one example of a planar structure of an imagingdevice 100A according to the present embodiment. FIG. 2 is a schematicsectional view taken along line II-II in FIG. 1.

As illustrated in FIG. 1, the imaging device 100A includes asemiconductor substrate 1 (see FIG. 2), a pixel region 30 in which aplurality of pixels 20 is arranged above the semiconductor substrate 1in a matrix, and a peripheral region 50 that is arranged at a peripheryof the pixel region 30 in plan view and that includes peripheralcircuitry.

The plurality of pixels 20 is, for example, two dimensionally arrangedabove the semiconductor substrate 1 to thereby form the pixel region 30.In the example illustrated in FIG. 1, the plurality of pixels 20 isarranged in row and column directions. The vertical direction in theplane in FIG. 1 corresponds to the column direction, and the lateraldirection corresponds to the row direction. In the illustrated inexample, the center of each pixel 20 is located at a grid point in asquare grid. Naturally, the arrangement of the pixels 20 is not limitedto the illustrated example, and for instance, the plurality of pixels 20may be arranged so that the center of each pixel 20 is located at a gridpoint in a triangular grid, a hexagonal grid, or the like. The pluralityof pixels 20 may also be arranged one dimensionally. In this case, theimaging device can be used as a line sensor.

In the configuration illustrated in FIG. 1, the peripheral region 50 isarranged at the periphery of the pixel region 30 in plan view andincludes the peripheral circuitry. The peripheral region 50 includesanalog circuitry, digital circuitry 33 a and 33 b, and wire regions 32 aand 32 b.

Examples of the analog circuitry include row scanning circuitry 31 a andcolumn circuitry 31 b. The row scanning circuitry 31 a includestransistors 22 (see FIG. 2) that constitute parts of the circuitry.Similarly, the column circuitry 31 b includes transistors (notillustrated) that constitute parts of the circuitry. The digitalcircuitry 33 a includes transistors 23 (see FIG. 2), and the digitalcircuitry 33 b includes transistors (not illustrated). The wire region32 a includes wires that provide connections between the row scanningcircuitry 31 a and the digital circuitry 33 a, and the wire region 32 bincludes wires that provide connections between the column circuitry 31b and the digital circuitry 33 b.

The peripheral circuitry includes the row scanning circuitry 31 a andthe digital circuitry 33 a arranged in the row direction and the columncircuitry 31 b and the digital circuitry 33 b arranged in the columndirection.

The wire regions 32 a and 32 b include wires, such as digital-signalwires, analog-signal wires, and power-supply wires. Each of the wiresmay be singularly arranged, or the wires may be arranged in a mixedmanner. The entire peripheral circuitry may be arranged above thesemiconductor substrate 1 above which the pixel region 30 is formed, orpart of the peripheral circuitry may be arranged on another substrate.

Based on address signals and control signals generated in the digitalcircuitry 33 a, the row scanning circuitry 31 a drives the pixels 20 tobe driven in the pixel region 30 through pixel-drive signal lines 21 a.In this case, the pixels 20 to be driven are selected for each row.Signal voltages from the selected pixels 20 are transmitted to thecolumn circuitry 31 b through vertical signal lines 21 b. The columncircuitry 31 b includes column signal processing circuitry (notillustrated) and column scanning circuitry. The column scanningcircuitry is also called horizontal signal reading circuitry. The columnsignal processing circuitry performs, for example, noise-suppressionsignal processing, typified by correlated double sampling, andanalog-to-digital conversion (AD conversion). The column scanningcircuitry is connected to the column signal processing circuitry, whichis provided so as to correspond to the columns of the pixels 20. Thecolumn scanning circuitry sequentially reads digital signals from thecolumn signal processing circuitry and transmits the digital signals tothe digital circuitry 33 b. Thus, signals from the pixels 20 driven foreach row are transmitted to outside via the digital circuitry 33 b.

Next, the configuration of a portion of the imaging device 100Aaccording to the present embodiment will be described in detail withreference to FIG. 2. FIG. 2 is a schematic sectional view taken alongline II-II in FIG. 1.

As illustrated in FIG. 2, the imaging device 100A includes thesemiconductor substrate 1, the pixel region 30 having the plurality ofpixels 20 formed above the semiconductor substrate 1, and the peripheralregion 50 that is arranged at the periphery of the pixel region 30 inplan view and that includes the peripheral circuitry. In the imagingdevice 100A, the pixel region 30 includes lower electrodes 3, an upperelectrode 5 that opposes the lower electrodes 3, a photoelectricconversion layer 4 provided between the lower electrodes 3 and the upperelectrode 5, and detection circuitry 11 located above the semiconductorsubstrate 1 to detect potentials of the lower electrodes 3.

In the pixel region 30, the detection circuitry 11 is provided across aninterface between the semiconductor substrate 1 and an insulating layer2 so as to correspond to the respective pixels 20. The lower electrodes3 are formed on a major surface of the insulating layer 2 at a positiveside (hereinafter referred to as an “upper side”) in the Z-axisdirection, that is, on an upper surface of the insulating layer 2. Thelower electrodes 3 are connected to the corresponding detectioncircuitry 11 through connection portions 12.

The lower electrodes 3 are electrodes for collecting charges generatedin the photoelectric conversion layer 4. The lower electrodes 3 are madeof, for example, metallic material, such as titanium nitride (TiN). Thelower electrodes 3 may also be made of copper (Cu), tungsten (W),titanium (Ti), tantalum (Ta), aluminum (Al), or a compound thereof. Thelower electrodes 3 have a uniform film thickness, and upper surfacesthereof are planarized.

The lower electrodes 3 are two dimensionally arranged on the uppersurface of the insulating layer 2 along two axes in the X-axis andY-axis directions. The lower electrodes 3 are arranged on the uppersurface of the insulating layer 2, for example, in a matrix and haveconstant gaps between the lower electrodes 3. The lower electrodes 3 arearranged so as to correspond to the arrangement of the pixels 20. Forexample, when the plurality of pixels 20 is arranged in a matrix, thelower electrodes 3 are arranged in a matrix so as to correspond to thearrangement of the pixels 20.

The detection circuitry 11 is provided so as to correspond to therespective lower electrodes 3. The detection circuitry 11 detects signalcharges collected by the corresponding lower electrodes 3 and outputssignal voltages corresponding to the charges. The detection circuitry 11is made of, for example, metal oxide semiconductor (MOS) circuitry orthin-film transistor (TFT) circuitry. The detection circuitry 11incudes, for example, amplifying transistors having gates connected tothe corresponding lower electrodes 3, and the amplifying transistorsoutput signal voltages corresponding to the amounts of signal charges.The detection circuitry 11 is light-shielded by a light-shielding layer(not illustrated) provided, for example, in the insulating layer 2.

The connection portions 12 provide electrical connections between thecorresponding lower electrodes 3 in the pixels 20 and the correspondingdetection circuitry 11. Connection portions 14 provide electricalconnection between a connection electrode 13 and a wiring layer. Theconnection portions 12 and 14 are formed, for example, by embeddingconductive material, such as copper (Cu) or tungsten (W), into theinsulating layer 2.

The insulating layer 2 is formed on the semiconductor substrate 1 andincludes constituent layers 2 a, 2 b, 2 c, 2 d, and 2 e (hereinaftersimply denoted as 2 a to 2 e). The semiconductor substrate 1 is made of,for example, silicon (Si). The constituent layers 2 a to 2 e are madeof, for example, silicon dioxide (SiO₂). For example, wiring layersincluding wires, contact plugs, and so on are provided in theconstituent layers 2 a to 2 e. The number of constituent layers in theinsulating layer 2 may be arbitrarily set and is not limited to theexample of five constituent layers 2 a to 2 e illustrated in FIG. 2.

The photoelectric conversion layer 4 is stacked on an upper surface ofthe constituent layer 2 e in which the lower electrodes 3 are arranged,and the upper electrode 5, a buffer layer 6, and a sealing layer 7 aresequentially stacked on an upper surface of the photoelectric conversionlayer 4. Color filters 8 having transmission wavelength bandscorresponding to the respective pixels 20 are formed on an upper surfaceof the sealing layer 7, and microlenses 10 are formed, with aplanarization layer 9 being interposed between the color filters 8 andthe microlenses 10.

The constituent layer 2 e in the insulating layer 2 is interposed in agap between the adjacent lower electrodes 3.

The photoelectric conversion layer 4 is a layer made of a photoelectricconversion material that generates charges in response to the strengthof received light and is sandwiched between the lower electrodes 3 andthe upper electrode 5. The photoelectric conversion material is, forexample, an organic semiconductor material and includes at least one ofa p-type organic semiconductor and an n-type organic semiconductor. Itis desirable that the photoelectric conversion layer 4 have a uniformfilm thickness in the pixel region 30.

The upper electrode 5 is an electrode that opposes the lower electrodes3. In plan view, the upper electrode 5 has a larger area than the pixelregion 30. As illustrated in FIG. 2, the upper electrode 5 is arrangedso that, in the pixel region 30, the upper electrode 5 opposes the lowerelectrodes 3, with the photoelectric conversion layer 4 being interposedbetween the lower electrodes 3 and the upper electrode 5. In addition,the upper electrode 5 is formed so as to extend in a negative direction(hereinafter may be referred to as “outside”) of the X-axis relative tothe pixel region 30 and overlaps the peripheral region 50 in plan view.

In the imaging device 100A according to the present embodiment, theupper electrode 5 has a first region 40 that overlaps the peripheralregion 50 in plan view. The first region 40 has a connection region 40 aconnected to the connection electrode 13 containing material that isdifferent from material of the upper electrode 5. That is, the upperelectrode 5 is connected to the connection electrode 13 in the firstregion 40 without the photoelectric conversion layer 4 being interposedtherebetween. The connection electrode 13 is connected to, for example,a reference potential through the connection portions 14.

The first region 40 may further have a non-connection region (notillustrated in FIG. 2), which is not connected to the connectionelectrode 13 in plan view, as described below.

In the present embodiment, the upper electrode 5 is arranged at a sideon which light is incident in the imaging device 100A. The upperelectrode 5 may have translucency in order to allow light to be incidenton the photoelectric conversion layer 4. The material of the upperelectrode 5 may be, for example, transparent oxide conductive material,such as indium tin oxide (ITO) or indium zinc oxide (IZO).

The connection electrode 13 is formed of a conductive material differentfrom the material of the upper electrode 5. For example, the connectionelectrode 13 may contain a highly conductive metallic material. In thiscase, the connection electrode 13 may contain material that is the sameas the material of the lower electrodes 3. For example, the connectionelectrode 13 may include at least one kind of copper (Cu), tungsten (W),titanium (Ti), tantalum (Ta), and aluminum (Al). The connectionelectrode 13 may also be a compound of these metallic materials.

The connection electrode 13 is arranged on a layer that is the same asthe layer on which the lower electrodes 3 are arranged. That is, theconnection electrode 13 and the lower electrodes 3 are in contact with asingle continuous layer (in FIG. 2, the constituent layer 2 e). When theconnection electrode 13 contains material that is the same as thematerial of the lower electrodes 3 and is arranged in a layer that isthe same as the layer in which the lower electrodes 3 are arranged, theconnection electrode 13 and the lower electrodes 3 can be formed at thesame time. This makes it possible to reduce the manufacturing time andthe manufacturing cost. Shield wires 15 may also be provided. The shieldwires 15 are described later. The lower electrode 3 exemplifies thefirst electrode. The upper electrode 5 exemplifies the second electrode.The connection electrode 13 exemplifies the third electrode.

Although not illustrated, a light-shielding layer is formed in a regionthat is located on the sealing layer 7 and that is other than the regionin which the color filters 8 are formed. Formation of thelight-shielding layer blocks external light to a region other than aneffective pixel region and prevents light incidence on the photoelectricconversion layer 4 in the region other than the effective pixel region.The “effective pixel region” as used herein means a region that isincluded in the pixel region and in which, for example, the pixelsexcept dummy pixels for detecting dark-time outputs and so on arearranged.

In addition, a pad region is provided at a perimeter of the imagingdevice 100A. In the pad region, a depression portion that penetrates theplanarization layer 9 and reaches the upper surface of the constituentlayer 2 d in the insulating layer 2 is provided, and a pad 19 is formedon a bottom surface of the depression portion. Although details are notillustrated, the pad 19 is electrically connected to signal input/outputcircuitry and circuitry for voltage supply and so on. A metal layer inthe peripheral region 50 is formed, for example, using copper (Cu).

Although, in the present embodiment, FIGS. 1 and 2 illustrate an examplein which the connection region 40 a in which the upper electrode 5 andthe connection electrode 13 are connected to each other is arrangedalong one side of the pixel region 30, the connection region 40 a may bearranged along two or more sides of the pixel region 30. The number ofsides along which the connection region 40 a is arranged may beincreased or reduced, as appropriate, considering the chip area and wirewidths in the imaging device. In embodiments other than the firstembodiment and modifications thereof (described below), the connectionregion 40 a may similarly be arranged along two or more sides of thepixel region 30.

Next, a description will be given of an image capture mechanism.

Light that is incident on the imaging device 100A from above passesthrough the sealing layer 7, the buffer layer 6, and the upper electrode5 and is incident on the photoelectric conversion layer 4. Thephotoelectric conversion layer 4 photoelectrically convert the incidentlight to generate charges in a state in which an appropriate biasvoltage is applied to the photoelectric conversion layer 4 by the lowerelectrodes 3 and the upper electrode 5. A potential difference betweenthe upper electrode 5 and the lower electrodes 3 acts as a bias voltageapplied to the photoelectric conversion layer 4.

The charges generated in the photoelectric conversion layer 4, asdescribed above, are transferred from the lower electrodes 3 tocorresponding accumulation regions in the detection circuitry 11 throughthe connection portions 12 and are temporarily accumulated. The chargesare then output to outside as signals via switching operations oftransistor elements or the like in the detection circuitry 11 at anappropriate timing.

The first region 40 in the imaging device 100A according to the presentembodiment overlaps the periphery of the pixel region 30, that is,elements and wires arranged in the peripheral region 50, in plan view,as illustrated in FIG. 2. Examples of the elements arranged in theperipheral region 50 include the transistors 22 in the row scanningcircuitry 31 a.

Since the first region 40 overlaps the elements and the wires, arrangedin the peripheral region 50, in plan view, as described above, it is notnecessary to increase the chip area. In other words, since the firstregion 40 can be arranged so as to overlap the peripheral region 50 inplan view, the chip area can be reduced compared with a knownconfiguration in which the upper electrode and the connection electrodeare connected to each other in a region other than the pixel region andthe peripheral region.

In the imaging device 100A, the upper electrode 5 covers more than halfof the lower electrodes 3 located in the pixel region 30. In thismanner, since the upper electrode 5 covers more than half of the lowerelectrodes 3 located in the pixel region 30, the area in which the upperelectrode 5 covers the photoelectric conversion layer 4 and the lowerelectrodes 3 can be increased in the pixel region 30. Accordingly, it ispossible to enhance the adhesion between the upper electrode 5 and thephotoelectric conversion layer 4 and the adhesion between thephotoelectric conversion layer 4 and the lower electrodes 3.

In the imaging device 100A, the upper electrode 5 covers the entirephotoelectric conversion layer 4. Since the upper electrode 5 covers theentire photoelectric conversion layer 4, the upper electrode 5 can coverall the pixels 20 included in the pixel region 30. In this case, sincethe upper electrode 5 has the first region 40 that overlaps theperipheral region 50 in plan view, it is possible to increase the areain which the upper electrode 5 covers the photoelectric conversion layer4, the lower electrodes 3, and peripheral portions thereof. This makesit possible to enhance the adhesion between the upper electrode 5 andthe photoelectric conversion layer 4 and the adhesion between thephotoelectric conversion layer 4 and the lower electrodes 3.

Second Embodiment

An overall configuration of an imaging device according to a secondembodiment will be described with reference to FIGS. 3 to 5. FIG. 3 is adiagram illustrating one example of a planar structure of an imagingdevice 1006 according to the present embodiment. FIG. 4 is a diagramillustrating an example of a planar structure of an imaging device 100Caccording to the present embodiment. FIG. 5 is a schematic sectionalview taken along line V-V in FIG. 3.

In the imaging device 100B illustrated in FIG. 3, the first region 40extends from the pixel region 30 toward a negative side in the X-axisdirection and overlaps the row scanning circuitry 31 a in plan view. TheX-axis direction in this case is the so-called row direction. In theimaging device 100C illustrated in FIG. 4, the first region 40 extendsfrom the pixel region 30 toward a positive side in the Y-axis directionand overlaps the column circuitry 31 b in plan view. The Y-axisdirection in this case is the so-called column direction. Each of therow scanning circuitry 31 a and the column circuitry 31 b is analogcircuitry.

Differences from the first embodiment will be described below.

In each of the imaging devices 100B and 100C in the present embodiment,the first region 40 further has a non-connection region 40 b, which isnot connected to the connection electrode 13 (see FIG. 5) in plan view.Since the first region 40 has the connection region 40 a and thenon-connection region 40 b, the area of the first region 40 increases.Accordingly, it is possible to increase the area in which the upperelectrode 5 covers the photoelectric conversion layer 4, the lowerelectrodes 3, and peripheral portions thereof, thus enhancing theadhesion between the upper electrode 5 and the photoelectric conversionlayer 4 and the adhesion between the photoelectric conversion layer 4and the lower electrodes 3. This makes it possible to more uniformlyapply a voltage to the photoelectric conversion layer 4 via the upperelectrode 5. Also, since the first region 40 overlaps the peripheralregion 50 in plan view, the chip area can be reduced compared with acase in which the first region 40 and the peripheral region 50 arearranged so as not to overlap each other. In addition, it is possible toincrease the ratio of a light-receiving area to the chip area. Also, thelength of the non-connection region may be made larger than the lengthof the connection region in the direction from the pixel region 30toward the peripheral region 50 (e.g., the negative direction on the Xaxis in FIG. 5). This makes it possible to further enhance the adhesionbetween the upper electrode 5 and the photoelectric conversion layer 4and the adhesion between the photoelectric conversion layer 4 and thelower electrodes 3.

Also, in each of the imaging devices 100B and 100C, the peripheralcircuitry has analog circuitry, and the first region 40 overlaps theanalog circuitry in plan view. In plan view, the peripheral circuitry isincluded in the peripheral region 50 arranged at the periphery of thepixel region 30. The analog circuitry included in the peripheralcircuitry includes the row scanning circuitry 31 a and column circuitry(not illustrated).

As described above, in the present embodiment, the first region 40further extends above the analog circuitry. This makes it possible toincrease the area in which the upper electrode 5 covers thephotoelectric conversion layer 4, the lower electrodes 3, and theperipheral portions thereof in plan view, thus making it possible toenhance the adhesion between the upper electrode 5 and the photoelectricconversion layer 4 and the adhesion between the photoelectric conversionlayer 4 and the lower electrodes 3.

In the present embodiment, the description has been given of an examplein which the first region 40 extends from the pixel region 30 to theleft side in the row direction or to the lower side in the columndirection, that is, an example in which the connection region 40 a isarranged along one side of the pixel region 30. The connection region 40a may also be arranged along two or more sides of the pixel region 30.For example, the first region 40 may extend from the pixel region 30 toboth left and right sides in the row direction or may extend to upperand lower sides in the column direction. The first region 40 may extendfrom the pixel region 30 to one side in the row direction or to one sidein the column direction. The first region 40 may extend from the pixelregion 30 to both the left and right sides in the row direction and boththe left and right sides in the column direction. That is, the firstregion 40 may be arranged along one or both of the left and right sidesof the pixel region 30 in plan view or may be arranged along one or bothof the upper and lower sides of the pixel region 30. The first region 40may also be arranged along four sides, that is, the upper, lower, left,and right sides, of the pixel region 30 in plan view.

When the connection region 40 a is arranged along two or more sides ofthe pixel region 30, as described above, the area of the first region 40increases compared with a case in which the connection region 40 a isarranged along only one side of the pixel region 30. This makes itpossible to ensure a large area in which the first region 40 overlapsthe insulating layer 2 in the peripheral region 50, thus making itpossible to enhance the adhesion of the upper electrode 5 to theinsulating layer 2. Also, since it is possible to increase the area inwhich the upper electrode 5 covers the photoelectric conversion layer 4,the lower electrodes 3, and the peripheral portions thereof, thus makingit possible to enhance the adhesion between the upper electrode 5 andthe photoelectric conversion layer 4 and the adhesion between thephotoelectric conversion layer 4 and the lower electrodes 3.

The configuration of a portion of the imaging device 100B according tothe present embodiment will be described below with reference to FIG. 5.FIG. 5 is a schematic sectional view taken along line V-V in FIG. 3.

Differences from the first embodiment will be described below.

In the imaging device 100B according to the present embodiment, thefirst region 40 further has the non-connection region 40 b, which is notconnected to the connection electrode 13 in plan view. The first region40 is a region in which the upper electrode 5 overlaps the peripheralregion 50 in plan view. Thus, at least either the non-connection region40 b or the connection region 40 a overlaps the peripheral region 50 inplan view.

In the present embodiment, the first region 40 overlaps the row scanningcircuitry 31 a in plan view. The row scanning circuitry 31 a includesthe transistors 22 as elements that constitute the row scanningcircuitry 31 a. In the example illustrated in FIG. 5, the non-connectionregion 40 b and the connection region 40 a both overlap, in plan view,elements that are included in the peripheral circuitry arranged at theperiphery of the pixel region 30 and that constitute the row scanningcircuitry 31 a. In the present embodiment, the arrangement is notlimited to this example, and it is sufficient that at least one of thenon-connection region 40 b and the connection region 40 a overlap, inplan view, the row scanning circuitry 31 a or wires that are connectedto the row scanning circuitry 31 a, for example, wires for connectingthe row scanning circuitry 31 a to external circuitry.

Since at least one of the connection region 40 a and the non-connectionregion 40 b in the first region 40 overlaps, in plan view, the elementsthat constitute the row scanning circuitry 31 a and the wires that areconnected to the row scanning circuitry 31 a, the elements and the wiresbeing included in the peripheral circuitry arranged at the periphery ofthe pixel region 30, it is possible to reduce the chip area. That is,since, in the present embodiment, the first region 40 overlaps theperipheral region 50 in plan view, an increase in the chip area can besuppressed compared with a known configuration in which the first region40 is provided without overlapping the peripheral region 50. This allowseach of the imaging devices 100B and 100C according to the presentembodiment to achieve a chip area that is equivalent to a chip area in atypical CMOS sensor using photodiodes.

In addition, with the above-described configuration, a larger area canbe ensured for the first region 40 than that in the known configuration,without increasing the chip area. This makes it possible to increase thearea in which the upper electrode 5 covers the photoelectric conversionlayer 4, the lower electrodes 3, and the peripheral portions thereof inplan view, thus making it possible to enhance the adhesion between theupper electrode 5 and the photoelectric conversion layer 4 and theadhesion between the photoelectric conversion layer 4 and the lowerelectrodes 3. Accordingly, in the pixel region 30, a more uniformvoltage can be applied to the photoelectric conversion layer 4 via theupper electrode 5. In addition, since the distance from an end portionof the upper electrode 5 to an end portion of the photoelectricconversion layer 4 increases, thus making it possible to reduce damageto the photoelectric conversion layer 4 during fabrication of the upperelectrode 5.

More specifically, for example, when the upper electrode 5 is patternedwith plasma, there are cases in which the end portion of the upperelectrode 5 is damaged. When the distance from the end portion of theupper electrode 5 to the end portion of the photoelectric conversionlayer 4 is large, the possibility that the photoelectric conversionlayer 4 is damaged can be reduced even if the end portion of the upperelectrode 5 is damaged.

First Modification of Second Embodiment

Next, an imaging device according to a first modification of the secondembodiment will be described with reference to FIGS. 6 and 7. FIG. 6 isa diagram illustrating one example of a planar structure of an imagingdevice 100D according to this modification. FIG. 7 is a schematicsectional view taken along line VII-VII in FIG. 6.

The above description in the second embodiment has been given of anexample in which the non-connection region 40 b is arranged at aposition closer to the pixel region 30 than the connection region 40 a,as illustrated in FIGS. 3 to 5. In the imaging device 100D according tothis modification, the connection region 40 a is arranged at a positioncloser to the pixel region 30 than the non-connection region 40 b, asillustrated in FIGS. 6 and 7. This modification also provides advantagesthat are the same as or similar to those in the second embodiment.

In embodiments below and modifications thereof, the connection region 40a may also be arranged at a position closer to the pixel region 30 thanthe non-connection region 40 b, as in this modification.

Third Embodiment

An overall configuration of an imaging device according to a thirdembodiment will be described with reference to FIGS. 8 to 10. FIG. 8 isa view illustrating one example of a planar structure of an imagingdevice 100E according to the present embodiment. FIG. 9 is a diagramillustrating an example of a planar structure of an imaging device 100Faccording to the present embodiment. FIG. 10 is a schematic sectionalview taken along line X-X in FIG. 8.

Differences from the first and second embodiments will be describedbelow. The present embodiment differs from the above-describedembodiments in that the first region 40 is arranged so as to extend fromthe pixel region 30 to the digital circuitry 33 a and 33 b.

More specifically, in the imaging device 100E illustrated in FIG. 8, thefirst region 40 extends from the pixel region 30 toward the negativeside in the X-axis direction and overlaps the row scanning circuitry 31a, the wire region 32 a, and the digital circuitry 33 a in plan view.Also, in the imaging device 100F illustrated in FIG. 9, the first region40 extends from the pixel region 30 toward the positive side in theY-axis direction and overlaps the column circuitry 31 b, the wire region32 b, and the digital circuitry 33 b in plan view.

The row scanning circuitry 31 a and the column circuitry 31 b are analogcircuitry. The wire region 32 a is a region including wires that provideconnections between the row scanning circuitry 31 a and the digitalcircuitry 33 a. The wire region 32 b includes wires that provideconnections between the column circuitry 31 b and the digital circuitry33 b.

As described above, the connection region 40 a in the first region 40may also be arranged along two or more sides of the pixel region 30. Thearrangement positions of the connection region 40 a and thenon-connection region 40 b in the first region 40 are not limited to theconfigurations illustrated in FIGS. 8 and 9. The connection region 40 amay be arranged at a position closer to the pixel region 30 than thenon-connection region 40 b.

The configuration of a portion of the imaging device 100E according tothe present embodiment will be described below with reference to FIG.10. FIG. 10 is a schematic sectional view taken along line X-X in FIG.8.

In the imaging device 100E according to the present embodiment, theperipheral circuitry has the digital circuitry 33 a. The first region 40overlaps the digital circuitry 33 a in plan view. For example, theperipheral circuitry has analog circuitry (in this case, the rowscanning circuitry 31 a) between the pixel region 30 and the digitalcircuitry 33 a. In plan view, the non-connection region 40 b overlapsthe row scanning circuitry 31 a, and the connection region 40 a overlapsthe digital circuitry 33 a.

Also, in plan view, since the first region 40 is arranged to extend tothe digital circuitry 33 a, the area of the first region 40 increases.This makes it possible to ensure a large area in which the upperelectrode 5 covers the photoelectric conversion layer 4, the lowerelectrodes 3, and the peripheral portions thereof. Accordingly, it ispossible to enhance the adhesion between the upper electrode 5 and thephotoelectric conversion layer 4 and the adhesion between thephotoelectric conversion layer 4 and the lower electrodes 3. Also, sinceit is not necessary to arrange the first region 40 so that it does notoverlap the peripheral region 50 in plan view, unlike the knownconfiguration, it is possible to suppress an increase in the chip area.

In addition, when the non-connection region 40 b is arranged so as tooverlap the row scanning circuitry 31 a, which is analog circuitry, andthe connection region 40 a is arranged so as to overlap the digitalcircuitry 33 a, as illustrated in FIG. 10, it is possible to reduceinfluences of the connection region 40 a on the peripheral circuitry.For example, a pulse voltage is applied to the connection region 40 a inorder to adjust the light-receiving sensitivity of the photoelectricconversion layer 4. In this case, there is a possibility that circuitryarranged in layers below the connection region 40 a is influenced by avoltage or electrical current in the connection region 40 a. Forexample, there is a possibility that an output of the circuitry variesowing to coupling with a voltage applied to the connection region 40 a.Alternatively, when light is incident on the upper electrode 5,electrical current flows in the upper electrode 5. When circuitry islocated in layers below the upper electrode 5, there is a possibilitythat an output of the circuitry varies owing to coupling with anelectrical current flowing in the upper electrode 5. In general, analogcircuitry is susceptible to noise, compared with digital circuitry.Accordingly, when the first region 40 is arranged to extend to thedigital circuitry 33 a, the connection region 40 a is arranged so as tooverlap the digital circuitry 33 a, and the non-connection region 40 bis arranged so as to overlap the analog circuitry, it is possible toreduce influences that the voltage or electrical current in the upperelectrode 5 has on the peripheral circuitry, particularly, the analogcircuitry.

In addition, in the present embodiment, shield wires 15 a are locatedbetween the pixel region 30 and the connection region 40 a in plan viewand are located between wires that are connected to the peripheralcircuitry and the upper electrode 5 in a plane orthogonal to thesemiconductor substrate 1. In FIG. 10, the shield wires 15 a arearranged in a layer below the non-connection region 40 b located betweenthe pixel region 30 and the connection region 40 a in plan view, thatis, in a region that is included in the constituent layer 2 d and thatcorresponds to the non-connection region 40 b. This makes it possible toreduce influences of noise on the peripheral circuitry located in thelayers below the non-connection region 40 b and the wires that areconnected to the peripheral circuitry. The shield wires 15 a may befloating wires, and a predetermined voltage may be applied thereto.

In the present embodiment, the description has been given of an examplein which the shield wires 15 a are located between the pixel region 30and the connection region 40 a in plan view. When the connection region40 a in the first region 40 is arranged at a position closer to thepixel region 30 than the non-connection region 40 b (although this caseis not illustrated), the shield wires 15 a may be arranged in a regionthat is included in a layer below the non-connection region 40 b andthat corresponds thereto. Also, a portion included in the peripheralregion 50 and not covered by the first region 40 may also have a shieldwire between the wires that are connected to the peripheral circuitryand the upper major surface of the insulating layer 2 in a planeorthogonal to the semiconductor substrate 1. This allows influences ofnoise on the peripheral circuitry and the wires that are connected tothe peripheral circuitry to be also reduced in a portion that isincluded in the peripheral region 50 and that is not covered by thefirst region 40.

Although an example in which the connection region 40 a is arrangedalong only one side of the pixel region 30 has been described above inthe present embodiment, the connection region 40 a may be arranged alongtwo or more sides of the pixel region 30. When the connection region 40a is arranged along two or more sides of the pixel region 30, it ispossible to ensure a large area in which the first region 40 and thelayers therebelow overlap each other, compared with a case in which theconnection region 40 a is arranged along only one side. That is, whenthe upper electrode 5 extends beyond the four sides of the photoelectricconversion layer 4 to cover the entire photoelectric conversion layer 4in plan view, it is possible to ensure a large area in which the firstregion 40 and the layers therebelow overlap each other at the four sidesof the photoelectric conversion layer 4. This makes it possible tofurther increase the area in which the upper electrode 5 covers thephotoelectric conversion layer 4 and the lower electrodes 3, thus makingit possible to further enhance the adhesion between the upper electrode5 and the photoelectric conversion layer 4 and the adhesion between thephotoelectric conversion layer 4 and the lower electrodes 3.

First Modification of Third Embodiment

Next, an imaging device according to a first modification of the thirdembodiment will be described with reference to FIG. 11. FIG. 11 is aview illustrating one example of a cross-sectional structure of animaging device 100G according to this modification.

Differences from the third embodiment will be described below.

An example in which one shield wire 15 a covers one transistor has beendescribed above in the third embodiment. In this modification, oneshield wire 15 b is arranged so that, in plan view, it overlaps a wirethat is connected to a corresponding transistor, which is a part of theperipheral circuitry. That is, each shield wire 15 b has a smaller areathan the area of the shield wire 15 a in plan view.

For example, when the area of the peripheral region 50 is relativelylarge, forming the shield wires 15 b so that, in plan view, they overlapthe corresponding wires that are connected to the peripheral circuitrymakes it possible to arrange a large number of shield wires 15 b in theperipheral region 50. This makes it possible to reduce influences ofnoise on the peripheral circuitry and the wires that are connected tothe peripheral circuitry.

Second Modification of Third Embodiment

Next, an imaging device according to a second modification of the thirdembodiment will be described with reference to FIG. 12. FIG. 12 is aview illustrating one example of the configuration of a section of animaging device 100H according to this modification.

In this modification, a shield wire 15 c is arranged in a region that isincluded in a layer below the non-connection region 40 b and thatcorresponds thereto. Specifically, the shield wire 15 c is arranged inthe constituent layer 2 d. As illustrated in FIG. 12, the shield wire 15c is arranged so as to cover, in plan view, a plurality of transistors,which are parts of the peripheral circuitry that overlaps thenon-connection region 40 b, and a plurality of wires that are connectedto the transistors.

Since the shield wire 15 c is formed with a large width so as to coverthe transistors and the wires in plan view, it is possible to enhanceshielding of noise in a wide range. Accordingly, it is possible tofurther reduce influences of noise on the peripheral circuitry and thewires that are connected to the peripheral circuitry.

Wires that are not used as the wires that are connected to the lowerelectrodes 3 or the peripheral circuitry may be used as theabove-described shield wires 15 a, 15 b, and 15 c.

Fourth Embodiment

An overall configuration of an imaging device according to a fourthembodiment will be described with reference to FIGS. 13 to 15. FIG. 13is a view illustrating one example of a planar structure of an imagingdevice 100I according to the present embodiment. FIG. 14 is a viewillustrating one example of a planar structure of an imaging device 100Jaccording to the present embodiment. FIG. 15 is a schematic sectionalview taken along line XV-XV in FIG. 13.

Differences from the first to third embodiments will be described below.The present embodiment differs from the above-described embodiments inthat the first region 40 is arranged so as to extend from the pixelregion 30 to the wire regions 32 a and 32 b.

In the imaging device 100I illustrated in FIG. 13, the first region 40extends from the pixel region 30 toward the negative side in the X-axisdirection and overlaps the row scanning circuitry 31 a and the wireregion 32 a in plan view. Also, in the imaging device 100J illustratedin FIG. 14, the first region 40 extends from the pixel region 30 towardthe positive side in the Y-axis direction and overlaps the columncircuitry 31 b and the wire region 32 b in plan view.

The wire region 32 a includes wires that provide connections between therow scanning circuitry 31 a and the digital circuitry 33 a. The wireregion 32 b includes wires that provide connections between columncircuitry (not illustrated) and digital circuitry (not illustrated).

Also, as described above, the connection region 40 a in the first region40 may be arranged along two or more sides of the pixel region 30. Thearrangement positions of the connection region 40 a and thenon-connection region 40 b in the first region 40 are not limited to theconfigurations illustrated in FIGS. 13 and 14. The connection region 40a may also be arranged at a position closer to the pixel region 30 thanthe non-connection region 40 b.

The configuration of a portion of the imaging device 100I according tothe present embodiment will be described below with reference to FIG.15. FIG. 15 is a schematic sectional view taken along line XV-XV in FIG.13.

In the present embodiment, the peripheral region 50 has the digitalcircuitry 33 a and the wire region 32 a. The wire region 32 a is locatedbetween the pixel region 30 and the digital circuitry 33 a and includeswires connected to the digital circuitry 33 a. The first region 40overlaps the wire region 32 a in plan view. For example, the peripheralregion 50 has analog circuitry (in this case, the row scanning circuitry31 a) located between the pixel region 30 and the wire region 32 a.Also, for example, in plan view, the non-connection region 40 b overlapsthe row scanning circuitry 31 a, and the connection region 40 a overlapsthe wire region 32 a.

Since the first region 40 is arranged above the wires connected to thedigital circuitry 33 a, as described above, it is possible to suppressan increase in the chip area without impairing characteristics of theperipheral circuitry. Now, suppose a case in which the connection region40 a is arranged so as to overlap the wire region 32 a in plan view. Inthis case, there is a possibility that owing to coupling between avoltage applied to the connection region 40 a and a voltage in wiresincluded in the wire region 32 a or coupling between electrical currentflowing in the upper electrode 5 and electrical current flowing in thewires included in the wire region 32 a, noise is introduced into outputsof the wires. However, the wires are connected to the digital circuitry33 a, which is relatively less susceptible to noise. Thus, even whennoise is introduced into outputs of the wires, the noise is less likelyto influence outputs of the digital circuitry 33 a. Accordingly, sincethe first region 40 is arranged so as to overlap the wire region 32 a inplan view, it is possible to reduce influences that the voltage orelectrical current of the upper electrode 5 has on the peripheralcircuitry. Also, since the first region 40 is arranged to extend to thewire region 32 a in plan view, the area of the first region 40increases. This makes it possible to ensure a large area in which theupper electrode 5 covers the photoelectric conversion layer 4 and thelower electrodes 3. Thus, it is possible to enhance the adhesion betweenthe upper electrode 5 and the photoelectric conversion layer 4 and theadhesion between the photoelectric conversion layer 4 and the lowerelectrodes 3. Also, it is not necessary to arrange the first region 40and the peripheral region 50 so that they do not overlap each other inplan view, unlike the known configuration, it is possible to increasethe chip area.

Also, as illustrated in FIG. 15, the non-connection region 40 b isarranged so as to overlap the row scanning circuitry 31 a, which isanalog circuitry, and the connection region 40 a is arranged so as tooverlap the wire region 32 a, it is possible to reduce influences of theconnection region 40 a on the peripheral circuitry. For example, a pulsevoltage is applied to the connection region 40 a in order to adjust thelight-receiving sensitivity of the photoelectric conversion layer 4. Insuch a case, there is a possibility that the circuitry arranged in thelayers below the connection region 40 a is influenced by noise. Ingeneral, analog circuitry is susceptible to noise, compared with digitalcircuitry. Accordingly, when the first region 40 is arranged to extendto the wire region 32 a, the connection region 40 a is arranged so as tooverlap the wire region 32 a, and the non-connection region 40 b isarranged so as to overlap the analog circuitry, it is possible to reduceinfluences of noise on the peripheral circuitry, particularly, theanalog circuitry.

Although an example in which the connection region 40 a is arrangedalong only one side of the pixel region 30 has been described above inthe present embodiment, the connection region 40 a may be arranged alongtwo or more sides of the pixel region 30. When the connection region 40a is arranged along two or more sides of the pixel region 30, it ispossible to ensure a large area in which the first region 40 and thelayers therebelow overlap each other, compared with a case in which theconnection region 40 a is arranged along one side of the pixel region30. That is, when the upper electrode 5 extends beyond the four sides ofthe photoelectric conversion layer 4 to cover the entire photoelectricconversion layer 4 in plan view, it is possible to ensure a large areain which the first region 40 and the layers therebelow overlap eachother at the four sides of the photoelectric conversion layer 4. Thismakes it possible to further increase the area in which the upperelectrode 5 covers the photoelectric conversion layer 4 and the lowerelectrodes 3, thus making it possible to further enhance the adhesionbetween the upper electrode 5 and the photoelectric conversion layer 4and the adhesion between the photoelectric conversion layer 4 and thelower electrodes 3.

Other Embodiments

Although an example in which the upper electrode 5 has the first region40 that overlaps the peripheral region 50 in plan view has beendescribed above in the first to fourth embodiments, the photoelectricconversion layer 4 may further have a region that overlaps theperipheral region 50 in plan view.

FIG. 16 is a view illustrating one example of a planar structure of animaging device 100K according to another embodiment. FIG. 17 is aschematic sectional view taken along line XVII-XVII in FIG. 16.

In the imaging device 100K illustrated in FIG. 16, the photoelectricconversion layer 4 extends from the pixel region 30 toward the negativeside in the X-axis direction and overlaps the row scanning circuitry 31a in plan view. Thus, the upper electrode 5, the buffer layer 6, and thesealing layer 7, which are stacked on the photoelectric conversion layer4, also extend from the pixel region 30 to the negative side in theX-axis direction. A region in which the photoelectric conversion layer 4overlaps the peripheral region 50, including the row scanning circuitry31 a and so on, in plan view is referred to as a “second region 41”.

Also, in the imaging device 100K, the upper electrode 5 has a largerarea than the photoelectric conversion layer 4 in plan view. The upperelectrode 5 also has the first region 40 that overlaps the peripheralregion 50.

As illustrated in FIG. 17, the first region 40 has the connection region40 a connected to the connection electrode 13. The connection electrode13 contains material that differs from material of the upper electrode5. The first region 40 may further have the non-connection region 40 b(not illustrated in FIG. 17), which is not connected to the connectionelectrode 13.

In the present embodiment, the first region 40 and the second region 41overlap the row scanning circuitry 31 a in plan view.

Since the photoelectric conversion layer 4 is formed so that the secondregion 41 overlaps the row scanning circuitry 31 a in plan view, asdescribed above, the thickness of the photoelectric conversion layer 4can be made uniform from an end portion of the pixel region 30 to acenter portion thereof, that is, throughout the pixel region 30.

When the photoelectric conversion layer 4 has the second region 41, asin the present embodiment, even if the film thickness at the end portionof the photoelectric conversion layer 4 becomes small during formationof the photoelectric conversion layer 4, the end portion of thephotoelectric conversion layer 4 is located outside the pixel region 30.Accordingly, the photoelectric conversion layer 4 can be formed so that,of the photoelectric conversion layer 4, only a portion having arelatively uniform film thickness is located in the pixel region 30. Asa result, since the pixels 20 can be uniformly formed regardless of thearrangement position of the pixels 20, it is possible to improve theuniformity of characteristics of the pixels 20.

Also, since the first region 40 overlaps the row scanning circuitry 31 ain plan view, the area in which the upper electrode 5 covers thephotoelectric conversion layer 4, the lower electrodes 3, and theperipheral portions thereof increases. Accordingly, it is possible toenhance the adhesion between the upper electrode 5 and the photoelectricconversion layer 4 and the adhesion between the photoelectric conversionlayer 4 and the lower electrodes 3. Since this makes it possible toenhance the uniformity of a voltage to be applied to the upper electrode5, a voltage to be applied to the photoelectric conversion layer 4 viathe connection region 40 a becomes uniform in the pixel region 30.

Although the imaging device according to the present disclosure has beendescribed above in conjunction with the embodiments and modifications,the present disclosure is not limited to the above-described embodimentsand modifications. Other embodiments implemented by combining arbitraryconstituent elements in the above-described embodiments andmodifications, modifications obtained by making various changesconceived by those skilled in the art to the above-described embodimentsand modifications within a scope not departing from the spirit of thepresent disclosure, and various types of equipment incorporating theimaging device according to the present disclosure are also encompassedby the scope of the present disclosure.

Although the description has been given of the imaging device in each ofthe above-described embodiments and modifications, the imaging deviceaccording to the present disclosure may also be applied to camerasystems.

FIG. 18 is a diagram illustrating one example of a camera systemincluding the imaging device in the present disclosure. Now, adescription will be given of a camera system 200 including the imagingdevice 100A according to the first embodiment.

The camera system 200 includes a lens optical system 201, the imagingdevice 100A, a system controller 202, and a camera signal processor 203.The lens optical system 201 includes, for example, a lens forautofocusing, a lens for zooming, and a diaphragm. The lens opticalsystem 201 concentrates light on an image capture plane of the imagingdevice 100A. The system controller 202 may be realized by, for example,a microcomputer. The camera signal processor 203 functions as signalprocessing circuitry that performs signal processing on data resultingfrom image capture performed by the imaging device 100A and outputs theresulting data as an image or data. The camera signal processor 203performs processing, for example, gamma correction, color interpolationprocessing, space interpolation processing, and white balancing. Thecamera signal processor 203 may be realized by, for example, a digitalsignal processor (DSP).

The imaging device 100A according to one aspect of the presentdisclosure can improve uniformity of the image quality withoutincreasing the chip area. Accordingly, use of such an imaging device100A makes it possible to improve uniformity of the image quality,without increasing the size of the camera system 200.

The imaging device according to the present disclosure is applicable tovarious camera systems and sensor systems. Examples of the camerasystems include a digital still camera, a medical camera, a camera formonitoring, a vehicle-mounted camera, a digital single-lens reflexcamera, and a digital mirrorless interchangeable lens camera.

What is claimed is:
 1. An imaging device comprising: a semiconductorsubstrate including a pixel region in which pixels are arranged and aperipheral region adjacent to the pixel region; an insulating layer thatcovers the pixel region and the peripheral region; a first electrodelocated on the insulating layer above the pixel region; a photoelectricconversion layer that covers the first electrode; a second electrodethat covers the photoelectric conversion layer; detection circuitrylocated in the pixel region and connected to the first electrode;peripheral circuitry located in the peripheral region and connected tothe detection circuitry; and a third electrode located on the insulatinglayer above the peripheral region, wherein the second electrode extendsabove the peripheral region, and the second electrode includes aconnection region in which the second electrode is connected to thethird electrode, the connection region overlapping the peripheralcircuitry in plan view.
 2. The imaging device according to claim 1,wherein the peripheral circuitry includes a transistor, and theconnection region overlaps the transistor in the plan view.
 3. Theimaging device according to claim 1, wherein the peripheral circuitryincludes analog circuitry connected to the detection circuitry, and theconnection region overlaps the analog circuitry in the plan view.
 4. Theimaging device according to claim 3, wherein the analog circuitryincludes a transistor, and the connection region overlaps the transistorin the plan view.
 5. The imaging device according to claim 1, whereinthe peripheral circuitry includes digital circuitry connected to thedetection circuitry, and the connection region overlaps the digitalcircuitry in the plan view.
 6. The imaging device according to claim 5,wherein the digital circuitry includes a transistor, and the connectionregion overlaps the transistor in the plan view.
 7. The imaging deviceaccording to claim 5, wherein the peripheral circuitry includes analogcircuitry connected between the digital circuitry and the detectioncircuitry, and the connection region does not overlap the analogcircuitry in the plan view.
 8. The imaging device according to claim 1,wherein the peripheral circuitry includes analog circuitry connected tothe detection circuitry, a wire connected to the analog circuitry, anddigital circuitry connected to the analog circuitry through the wire;and the connection region overlaps the wire in the plan view.
 9. Theimaging device according to claim 1, wherein the peripheral circuitryincludes analog circuitry connected to the detection circuitry, and awire for connecting the analog circuitry to external circuitry, and theconnection region overlaps the wire in the plan view.
 10. The imagingdevice according to claim 1, wherein the second electrode includes,above the peripheral region, a first region in which the photoelectricconversion layer is not present between the second electrode and theinsulating layer, and the first region includes the connection regionand a non-connection region other than the connection region.
 11. Theimaging device according to claim 10, wherein, in a direction from thepixel region toward the peripheral region, the non-connection region hasa length that is greater than a length of the connection region.
 12. Theimaging device according to claim 1, wherein, in the plan view, thesecond electrode has an area that is larger than an area of the pixelregion.
 13. The imaging device according to claim 10, furthercomprising: a shield wire located, in the plan view, between thenon-connection region and the peripheral circuitry or between thenon-connection region and a wire connected to the peripheral circuitry.14. The imaging device according to claim 13, wherein the peripheralcircuitry includes analog circuitry, and the shield wire is located, inthe plan view, between the non-connection region and the analogcircuitry or between the non-connection region and a wire connected tothe analog circuitry.
 15. The imaging device according to claim 1,wherein the pixels are arranged on the pixel region in a matrix, and theconnection region is arranged along two or more sides of the pixelregion.
 16. The imaging device according to claim 1, wherein the secondelectrode covers more than half of first electrodes located above thepixel region.
 17. The imaging device according to claim 1, wherein thethird electrode and the first electrodes are in contact with a singlecontinuous layer.
 18. The imaging device according to claim 1, whereinthe third electrode contains a material that is the same as a materialthat the first electrode contains.
 19. The imaging device according toclaim 1, wherein the third electrode contains at least copper, tungsten,titanium, tantalum, or aluminum.
 20. The imaging device according toclaim 1, wherein the second electrode covers an entire portion of thephotoelectric conversion layer.